Why "filled a lawsuit" won’t hold up in court

What kind of error is it?

Spelling/Typographical Error

Why do people make this mistake?

This error may arise from a typographical mistake or a misunderstanding of the correct phrase. People might accidentally type "filled" instead of "filed" either due to a typing slip or a lapse in correctly recalling the legal terminology.

What is correct?

The correct phrase is "filed a lawsuit". This is the standard legal terminology used to indicate that someone has officially submitted a legal case to a court.